Symptom Chart — Turbocharger Diagnosis

TURBOCHARGER DIAGNOSIS

Condition	Possible Source	Action
No Boost	Compressor air intake hose collapsed.	SERVICE as required.
	Intake manifold hoses leaking.	TIGHTEN hose clamps.
	Turbocharger turbine or compressor wheel damaged. Turbocharger bearings seized.	REPLACE turbocharger. REFER to Turbocharger Removal and Installation in this section.
	Clogged air cleaner element or restriction upstream of compressor.	SERVICE as required.
Lack of Power	Engine. Low compression.	REFER to Powertrain Control/Emissions Diagnosis Manual OBDI.
	Clogged air cleaner element or restriction upstream of compressor. Insufficient fuel supply.	SERVICE as required.
	Restriction.	REFER to Powertrain Control/Emissions Diagnosis Manual OBDI.
Excessive Fuel Consumption (Black Exhaust Smoke)	High fuel pressure. Pressure regulator.	SERVICE as required. REFER to Powertrain Control/Emissions Diagnosis Manual OBDI.
	Fuel return line plugged or kinked. Injectors leaking.	CLEAN or REPLACE as required.
	Powertrain control module malfunctioning.	REFER to Powertrain Control/Emissions Diagnosis Manual OBDI.
Excessive Oil Consumption (Blue, Gray, or White Exhaust Smoke)	Incorrect type or grade of oil.	DRAIN and FILL with specified oil.
	Extended oil change intervals.	CHANGE oil as recommended.
	Clogged air cleaner element or restriction upstream of compressor.	SERVICE as required.
	Engine wear (piston rings, valve guides). Turbocharger oil seals leaking.	SERVICE as required.
	Injector or injector O-ring leaking.	REFER to Pinpoint Test A.
Noise or Vibration	Leaks at turbocharger inlet and outlet connections.	SERVICE as required.
	Foreign object damage to turbine or compressor blades.	REPLACE turbocharger. REFER to Turbocharger Removal and Installation in this section.
	Turbine bearing failure.	REPLACE turbocharger. REFER to Turbocharger Removal and Installation in this section.
High Boost	Leak in exhaust system before muffler.	SERVICE as required.